Proper attachment and orientation of a tether to a helmet used by race car drivers is critical to proper function of a helmet restraint system. Typically, a helmet has a pair of tether anchors, one located on each side of the helmet proximate to a user's ear. The tether anchor detachably connects to a tether clip, which in turn is connected to a tether strap that is part of a head and neck restraint apparatus worn about the user's neck, shoulders and torso to reduce injury in the event of a crash or other incident. The tether strap is constructed to have a specific useable length to limit forward-backward movement of the user's head, but permit limited turning of the head. Many helmet restraint systems require the length of the tether to be adjusted, or personalized, to the specific user's physique. If the tether anchor is attached to the helmet improperly, such as the tether clip being attached upside down, the tether strap may become twisted, which reduces the effective usable length of the tether, which in turn excessively restricts movement of the user's head. It would be desirable to have a tether clip and anchor assembly that would prevent improper attachment of the tether strap. It would also be desirable to have a tether clip and anchor assembly that would be easy for a user to attach with minimal effort, yet remain secure and in the proper orientation during use. It would be further desirable to have a tether clip and anchor assembly that would have reduced likelihood of undesirable decoupling when a crash force causes tension in the strap to be nonorthogonal to the anchor assembly and nonparallel to the tether clip.